3 8o 



COMPOSITAE. 



VOL. III. 



i. Isopappus divaricatus (Nutt.) T. & G. 

 Isopappus. Fig. 4212. 



Inula divaricata Nutt. Gen. 2: 152. 1818. 



Aplopappus divaricatus A. Gray, Syn. Fl. i : Part 2, 130. 

 1884. 



Isopappus divaricatus T. & G. Fl. N. A. 2 : 239. 1841. 



Annual or biennial, erect, paniculately much 

 branched, slender, rough-pubescent or glandular, 

 l-3 high. Leaves linear, linear-lanceolate, or the 

 lowest linear-spatulate, acute or cuspidate, dentate 

 with distant teeth, or sometimes entire, i'-3' long, 

 I "-3" wide, the uppermost much smaller, subulate 

 or bract-like; heads numerous, 3"-5" broad; invo- 

 lucre campanulate, its bracts linear-lanceolate, subu- 

 late-tipped, pubescent, peduncles very slender, or 

 filiform. 



In dry soil, Kansas to Texas, east to Georgia and Flor- 

 ida. Aug.-Oct. 



22. SOLIDAGO L. Sp. PI. 878. 1753. 



Perennial erect herbs, sometimes woody at the base, simple, or little branched, with alter- 

 nate simple toothed or entire leaves, and small heads of both tubular and radiate, yellow or 

 rarely white flowers, in terminal or axillary panicles, thyrsi, or cymose-corymbose or capitate 

 clusters. Involucre oblong or narrowly campanulate, its bracts imbricated in several series, 

 the outer successively shorter. Receptacle small, flat, or somewhat convex, generally alveo- 

 late. Ray-flowers in one series, pistillate. Disk-flowers mostly all perfect, their corollas 

 tubular or narrowly campanulate, 5-cleft or 5-lobed. Anthers obtuse and entire at the base. 

 Style-branches flattened, their appendages lanceolate. Achenes terete or angled, usually 

 ribbed. Pappus of numerous capillary rough nearly equal bristles in I or 2 series. [Greek, 

 to make whole.] Golden-rod; also called yellow-top, yellow-weed or flower-of-gold. 



About 125 species, mostly of North America, 2 or 3 in Europe, a few in Mexico and South 

 America. Type species : Solidago Virgaurea L. 



A. Tips of the involucral bracts, or some of them spreading or recurved. 



Leaves glabrous or glabrate, 4'-io' long. 

 Leaves rough-ciliate, \'-z' long. 



1. 5". squarrosa. 



2. S. petiolaris. 



B. Tips of the involucral bracts all erect and appressed. 



* Heads in axillary clusters, or also in a terminal spike-like, sometimes branched thyrsus. 

 i. Heads 2"$" high, chiefly in axillary clusters ; achenes pubescent. 



Stem and branches terete ; leaves lanceolate to oblong. 

 Stem and branches grooved or angled. 



Leaves broadly oval, contracted into margined petioles. 



Leaves lanceolate, sessile. 



4. 5". fle.vicaulis. 



5. .S". Curtisii. 



2. Heads 2"-$" high, chiefly in a terminal spike-like thyrsus ; achenes glabrous, or nearly so. 



Rays white ; stem pubescent. 



Rays yellow ; stem densely pubescent. 



Rays yellow ; stem glabrous, or sparingly pubescent. 



Leaves thick, not acuminate, dentate, or the upper entire. 



Leaves thin, acuminate, sharply serrate. 



6. S. bicolor. 



7. S. hispida. 



8. 5". erec'a. 



9. 5". monticola. 



3. Heads s"-6" high ; bracts elongated, acute ; leaves ovate. 10. S.macrophylla. 

 ** Heads in a terminal simple or branched thyrsus, not at all secund on its branches, or scarcely so. 



Plant rough-pubescent or scabrous; leaves sessile, entire; bracts acute. n. S. Lindheimeriana. 



Plants glabrous, puberulent, or sparingly pubescent above. 

 Low arctic-alpine species, seldom over 10' high. 

 Heads with 30 flowers or more. 

 Heads with fewer than 30 flowers. 

 Taller species, not arctic-alpine. 



Bracts of the involucre linear-subulate, very acute; stem puberulent. 14. S.puberula. 

 Bracts of the involucre obtuse or merely acutish ; stem glabrous, or sparingly pubescent above. 

 Glabrous throughout; upper leaves very small, appressed. 15. S.stricta. 



At least the involucre or peduncles pubescent or puberulent. 



12. 5". Cutleri. 



13. S. multiradiata. 



